This neuropsychological core will provide centralized, cost-effective data collection. It will coordinate reliable neuropsychological test administration, scoring, and data collation. The goal of Core D is to further define observed attention and memory deficits in Lyme disease and to more fully characterize neurobehavioral function in adult and pediatric patients with early and late stages of infection. The specific aims of the Core are: 1. To coordinate neuropsychological data collection in a cost-effective manner 2. To provide a centralized and standardized means of assessment which is consistent across Projects and subject groups. 3. To provide initial data reduction in preparation for project specific statistical analyses 4. To train and supervise study psychometricians 5. To ensure quality assurance with respect to all neuropsychological assessment procedures.